Identification and characterization of BGL11(t), a novel gene regulating leaf-color mutation in rice (Oryza sativa L.)

A novel bright-green leaf mutant, bgl11, derived from Nipponbare (Oryza sativa L. ssp. japonica) treated by ethyl methanesulfonate (EMS), exhibited a distinct bright-green leaf phenotype throughout development. Chlorophyll contents of bgl11 decreased significantly than that of its wild-type parent. Genetic analysis suggested that the bright-green leaf trait was controlled by a single recessive nuclear gene, which was tentatively designed as BGL11(t). To isolate the BGL11(t) gene, a map-based cloning strategy was employed, and the gene was finally mapped in a 94.7 kb region between marker InDel11-5 and InDel11-9 on the long arm of chromosome 11, in which no gene leaded to leaf-color mutation had been mapped or cloned. Cloning and sequencing analysis revealed that, LOC_Os11g38040, which was predicted to encode an expressed protein, had a 9 bp segment deletion in the coding region of bgl11. Furthermore, the transgenic plants with wild-type gene LOC_Os11g38040 were restored to normal phenotype. Accordingly, the gene (LOC_Os11g38040) was identified as the BGL11(t) gene. These results are very valuable for further study on BGL11(t) gene and illuminating the mechanism of chloroplast development in rice.